Lubrication and Wear in Forging
Both hot and cold forgings are batch-type processes in which steady-state conditions are never fully achieved and the initial lubricant supply must perform adequately for the duration of the operation. This article discusses methods to measure lubricant effectiveness and wear. It describes the mixed-film lubrication and solid film lubrication in cold forging, as well as solid film lubrication and thick film lubrication in hot forging. The article reviews the factors affecting abrasive wear: die hardness, workpiece temperature, and lubrication and die temperature. It concludes with information on ways to improve resistance to abrasive wear.